Showing papers by "University of Warsaw published in 2006"
TL;DR: It is found that the minimum conductivity of order e2/h at the Dirac point (when the electron and hole excitations are degenerate) is associated with a maximum of the Fano factor (the ratio of noise power and mean current).
Abstract: We calculate the mode-dependent transmission probability of massless Dirac fermions through an ideal strip of graphene (length $L$, width $W$, no impurities or defects) to obtain the conductance and shot noise as a function of Fermi energy. We find that the minimum conductivity of order ${e}^{2}/h$ at the Dirac point (when the electron and hole excitations are degenerate) is associated with a maximum of the Fano factor (the ratio of noise power and mean current). For short and wide graphene strips the Fano factor at the Dirac point equals $1/3$, 3 times smaller than for a Poisson process. This is the same value as for a disordered metal, which is remarkable since the classical dynamics of the Dirac fermions is ballistic.
724 citations
TL;DR: A growing number of applications of carbon nanotubes (CNTs) in analytical chemistry are discussed in this paper, where the largest number of reported applications concern design of novel gas sensors, voltammetry, enzymatic biosensors, immunosensors and DNA probes.
Abstract: Discoveries of new materials have significant impact on development of new methods and instrumentation for chemical analysis. Based on 104 references, this article illustrates a growing number of applications of carbon nanotubes (CNTs) in analytical chemistry. The largest numbers of reported applications concern design of novel gas sensors, voltammetry, enzymatic biosensors, immunosensors and DNA probes. The sorptive properties of CNTs are also employed for analytical purposes in various ways.
681 citations
TL;DR: In this article, measurements of {nu}{sub {mu}} disappearance in K2K, the KEK to Kamioka long-baseline neutrino oscillation experiment are presented.
Abstract: We present measurements of {nu}{sub {mu}} disappearance in K2K, the KEK to Kamioka long-baseline neutrino oscillation experiment. One-hundred and twelve beam-originated neutrino events are observed in the fiducial volume of Super-Kamiokande with an expectation of 158.1{sub -8.6}{sup +9.2} events without oscillation. A distortion of the energy spectrum is also seen in 58 single-ring muonlike events with reconstructed energies. The probability that the observations are explained by the expectation for no neutrino oscillation is 0.0015% (4.3{sigma}). In a two-flavor oscillation scenario, the allowed {delta}m{sup 2} region at sin{sup 2}2{theta}=1 is between 1.9 and 3.5x10{sup -3} eV{sup 2} at the 90% C.L. with a best-fit value of 2.8x10{sup -3} eV{sup 2}.
672 citations
TL;DR: In this article, the authors summarized the current knowledge on the different pools and fluxes of Si in soils and terrestrial biogeosystems, including the contribution of the biogenic sources to Si redistribution within soil profiles and desilication.
Abstract: Silicon (Si) is the second-most abundant element in the earth's crust. In the pedosphere, however, huge spans of Si contents occur mainly caused by Si redistribution in soil profiles and landscapes. Here, we summarize the current knowledge on the different pools and fluxes of Si in soils and terrestrial biogeosystems. Weathering and subsequent release of soluble Si may lead to (1) secondarily bound Si in newly formed Al silicates, (2) amorphous silica precipitation on surfaces of other minerals, (3) plant uptake, formation of phytogenic Si, and subsequent retranslocation to soils, (4) translocation within soil profiles and formation of new horizons, or (5) translocation out of soils (desilication). The research carried out hitherto focused on the participation of Si in weathering processes, especially in clay neoformation, buffering mechanisms for acids in soils or chemical denudation of landscapes. There are, however, only few investigations on the characteristics and controls of the low-crystalline, almost pure silica compounds formed during pedogenesis. Further, there is strong demand to improve the knowledge of (micro)biological and rhizosphere processes contributing to Si mobilization, plant uptake, and formation of phytogenic Si in plants, and release due to microbial decomposition. The contribution of the biogenic Si sources to Si redistribution within soil profiles and desilication remains unknown concerning the pools, rates, processes, and driving forces. Comprehensive studies considering soil hydrological, chemical, and biological processes as well as their interactions at the scale of pedons and landscapes are necessary to make up and model the Si balance and to couple terrestrial processes with Si cycle of limnic, fluvial, or marine biogeosystems.
527 citations
TL;DR: In this paper, four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the minimal supersymmetric standard model (MSSM).
Abstract: The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric standard model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of “benchmark” models, including CP-conserving and CP-violating scenarios. These interpretations lead in all cases to large exclusions in the MSSM parameter space. Absolute limits are set on the parameter cosβ and, in some scenarios, on the masses of neutral Higgs bosons.
494 citations
TL;DR: The results of the second phase of the Super-Kamiokande solar neutrino measurement are presented and compared to the first phase in this paper, showing no evidence of systematic tendencies between the first and second phases.
Abstract: The results of the second phase of the Super-Kamiokande solar neutrino measurement are presented and compared to the first phase. The solar neutrino flux spectrum and time variation as well as oscillation results are statistically consistent with the first phase and do not show spectral distortion. The time-dependent flux measurement of the combined first and second phases coincides with the full period of solar cycle 23 and shows no correlation with solar activity. The measured {sup 8}B total flux is (2.38{+-}0.05(stat.){sub -0.15}{sup +0.16}(sys.))x10{sup 6} cm{sup -2} s{sup -1} and the day-night difference is found to be (-6.3{+-}4.2(stat.){+-}3.7(sys.))%. There is no evidence of systematic tendencies between the first and second phases.
439 citations
Durham University1, University of Helsinki2, University of Wisconsin-Madison3, University of Rochester4, University of Catania5, Weizmann Institute of Science6, University of Warsaw7, University of Southampton8, CERN9, Lawrence Livermore National Laboratory10, Indian Institute of Science11, University of Montpellier12, University of Zurich13, Spanish National Research Council14, ETH Zurich15, Stanford University16, Northwestern University17, University of Pittsburgh18, Carleton University19, University of Hamburg20, Moscow State University21, University of Florida22, Paul Scherrer Institute23, University of Würzburg24, Imperial College London25, Florida State University26, University of Florence27, University of Bonn28, University at Buffalo29, RWTH Aachen University30, University of Sheffield31, University of California, Irvine32, Laboratoire d'Annecy-le-Vieux de physique des particules33, Brookhaven National Laboratory34, Argonne National Laboratory35, University of Bergen36, University of Mainz37, Centers for Medicare and Medicaid Services38, Lancaster University39, University of California, Santa Cruz40, University of Copenhagen41, University of Tokyo42, Austrian Academy of Sciences43, University of Manchester44, University College London45, University of Edinburgh46, University of California, Davis47, University of California, Berkeley48, University of Glasgow49, University of Barcelona50, Max Planck Society51, University of Chicago52, University of Turin53, Royal Holloway, University of London54, Kobe University55, University of Oslo56, Kyoto University57
TL;DR: In this paper, the authors discuss the possible interplay between the Large Hadron Collider (LHC) and the International e(+)e(-) Linear Collider (ILC) in testing the Standard Model and in discovering and determining the origin of new physics.
422 citations
01 Jan 2006
385 citations
TL;DR: In this paper, it was shown that there is only one cyclic representation invariant under spatial diffeomorphisms, and this invariance can be used for any theory in which the configuration variable is a connection with a compact structure group.
Abstract: Loop quantum gravity is an approach to quantum gravity that starts from the Hamiltonian formulation in terms of a connection and its canonical conjugate. Quantization proceeds in the spirit of Dirac: First one defines an algebra of basic kinematical observables and represents it through operators on a suitable Hilbert space. In a second step, one implements the constraints. The main result of the paper concerns the representation theory of the kinematical algebra: We show that there is only one cyclic representation invariant under spatial diffeomorphisms. While this result is particularly important for loop quantum gravity, we are rather general: The precise definition of the abstract *-algebra of the basic kinematical observables we give could be used for any theory in which the configuration variable is a connection with a compact structure group. The variables are constructed from the holonomy map and from the fluxes of the momentum conjugate to the connection. The uniqueness result is relevant for any such theory invariant under spatial diffeomorphisms or being a part of a diffeomorphism invariant theory.
342 citations
TL;DR: The concept of pullback asymptotically compact non-autonomous dynamical systems was introduced in this article, which means the existence of a (random or time dependent) family of compact attracting sets.
Abstract: First, we introduce the concept of pullback asymptotically compact non-autonomous dynamical system as an extension of the similar concept in the autonomous framework. Our definition is different from that of asymptotic compactness already used in the theory of random and non-autonomous dynamical systems (as developed by Crauel, Flandoli, Kloeden, Schmalfuss, amongst others) which means the existence of a (random or time-dependent) family of compact attracting sets. Next, we prove a result ensuring the existence of a pullback attractor for a non-autonomous dynamical system under the general assumptions of pullback asymptotic compactness and the existence of a pullback absorbing family of sets. This attractor is minimal and, in most practical applications, it is unique. Finally, we illustrate the theory with a 2D Navier–Stokes model in an unbounded domain.
340 citations
TL;DR: In this article, a theoretical study of double compact objects as potential short/hard gamma-ray burst (GRB) progenitors is presented, and their formation rates, estimate merger times, and finally predict their most likely merger locations and afterglow properties for different types of host galaxies.
Abstract: We present a theoretical study of double compact objects as potential short/hard gamma-ray burst (GRB) progenitors. An updated population synthesis code, StarTrack, is used to calculate properties of double neutron stars and black hole-neutron star binaries. We obtain their formation rates, estimate merger times, and finally predict their most likely merger locations and afterglow properties for different types of host galaxies. Our results serve for a direct comparison with the recent HETE-2 and Swift observations of several short bursts, for which afterglows and host galaxies were detected. We also discuss the possible constraints these observations put on the evolutionary models of double compact object formation. We emphasize that our double compact object models can successfully reproduce at the same time short GRBs within both young, star-forming galaxies (e.g., GRB 050709 and GRB 051221A), as well as within old, elliptical hosts (e.g., GRB 050724 and probably GRB 050509B).
TL;DR: It is shown that a single photon absorbed by the N atoms will be followed by spontaneous emission in the same direction, and phase matched emission is found when one photon is absorbed by N atoms followed by two-photon down-conversion.
Abstract: A collection of $N$ static atoms is fixed in a crystal at a low temperature and prepared by a pulse of incident radiation of wave vector ${\stackrel{\ensuremath{\rightarrow}}{k}}_{0}$. The $N$ atoms are well described by an entangled Dicke-like state, in which each atom carries a characteristic phase factor $\mathrm{exp} (i{\stackrel{\ensuremath{\rightarrow}}{k}}_{0}\ifmmode\cdot\else\textperiodcentered\fi{}{\stackrel{\ensuremath{\rightarrow}}{r}}_{j})$, where ${\stackrel{\ensuremath{\rightarrow}}{r}}_{j}$ is the atomic position in the crystal. It is shown that a single photon absorbed by the $N$ atoms will be followed by spontaneous emission in the same direction. Furthermore, phase matched emission is found when one photon is absorbed by $N$ atoms followed by two-photon down-conversion.
TL;DR: Comparative modeling based on more than 30% sequence identity is now approaching its natural template-based limits and further improvements require the development of effective refinement techniques capable of driving models toward native structure.
Book•
Mälardalen University College1, University of Warwick Science Park2, Aalborg University3, University of Gothenburg4, Masaryk University5, Bielefeld University6, University of Warsaw7, University of Łódź8, University of Tampere9, Hanken School of Economics10, University of the West of England11, Tallinn University12, University of Latvia13
TL;DR: The separation of home and work is both a very real one and an ideological construction as mentioned in this paper, and it is at the root of much liberal social science, as well as figuring, in more or less sophisticated ways, in non-feminist (Habermas, 1984, 1987) and feminist (Fraser, 1989) critical theory.
Abstract: The social relations of home and work represent some of the most fundamental aspects of gender relations in society, and thus some of the most important elements in the construction of men and masculinities. The separation of home and work is both a very real one and an ideological construction. It is at the root of much liberal social science, as well as figuring, in more or less sophisticated ways, in non-feminist (Habermas, 1984, 1987) and feminist (Fraser, 1989) critical theory. In some ways it refers to the distinction between production and reproduction; but an over-simple division into dual spheres has been shown to be theoretically flawed, historically inaccurate (Bose, 1987; Hearn, 1992) and contrary to the experience of some people and some social categories, for example, women of colour (Collins, 1990).
TL;DR: In this paper, the authors address the question why fear dominates hope in the life of individuals and collectives on the basis of the accumulated knowledge in the psychology, neurology and sociology of emotions.
Abstract: We address the question why fear dominates hope in the life of individuals and collectives on the basis of the accumulated knowledge in the psychology, neurology and sociology of emotions. This knowledge suggests that fear, as primary emotion, is grounded in the experienced present and based on the memorized past, processed both consciously and unconsciously, causes freezing and conservatism, and sometimes leads to pre-emptive aggression. Hope, in contrast, as a secondary emotion, involves cognitive activity, which requires anticipation and the search for new ideas and thus is based on complex processes of creativity and flexibility. Therefore, hope is often preceded and inhibited by spontaneous, automatically activated and faster fear. Fear and hope can each become a collective emotional orientation, and as such organize society’s views and direct its actions. Societies involved in intractable conflict are dominated by a collective fear orientation. This orientation is functional for society’s coping with the stressful and demanding situation—but it may serve as a psychological obstacle to any peace process, once it starts. The case of the collective fear orientation in the Jewish Israeli society is presented as an example. The article ends with a presentation of a particular approach, suggesting that individuals and collectives can overcome their fear with much determination, and establish an orientation of hope which allows change in situations dominated by fear. Copyright # 2006 John Wiley & Sons, Ltd.
University of Lisbon1, University of Cambridge2, Texas A&M University3, Florida State University4, Johns Hopkins University5, Argonne National Laboratory6, University of Wisconsin-Madison7, Lawrence Berkeley National Laboratory8, University of Vienna9, Stanford University10, Michigan State University11, Royal Holloway, University of London12, Moscow State University13, Fermilab14, Chonbuk National University15, CERN16, University of Freiburg17, Pontifical Catholic University of Chile18, University of Paris19, University of Delhi20, Austrian Academy of Sciences21, National Autonomous University of Mexico22, University of Würzburg23, University of Zurich24, Max Planck Society25, Indian Institute of Science26, Aristotle University of Thessaloniki27, University of Barcelona28, University of California, Davis29, University of Tokushima30, University of California, Santa Cruz31, University of Science and Technology of China32, Tsinghua University33, Uppsala University34, Tokyo Gakugei University35, Spanish National Research Council36, National Taiwan University37, University of Liverpool38, University of Warsaw39, University of Michigan40, Seoul National University41, Yonsei University42, University of Southampton43, University of Bonn44, University of Montpellier45, RWTH Aachen University46, Laboratoire d'Annecy-le-Vieux de physique des particules47, University of Pennsylvania48, Carleton University49, University of Florida50, University of Glasgow51, University of Tokyo52, University of Lyon53, Harish-Chandra Research Institute54, University of Colorado Boulder55, Kyoto University56, University of Minnesota57, University of Rochester58, Durham University59, Tata Institute of Fundamental Research60, Paul Scherrer Institute61, University of Hamburg62, Chung-Ang University63, University of Sheffield64, University of Chicago65, Tohoku University66, Peking University67
TL;DR: In this article, a supersymmetry Parameter Analysis SPA (SPA) scheme is proposed based on a consistent set of conventions and input parameters, which connect parameters in different schemes and relate the Lagrangian parameters to physical observables at LHC and high energy e(+)e(-) linear collider experiments, i.e., masses, mixings, decay widths and production cross sections for supersymmetric particles.
Abstract: High-precision analyses of supersymmetry parameters aim at reconstructing the fundamental supersymmetric theory and its breaking mechanism. A well defined theoretical framework is needed when higher-order corrections are included. We propose such a scheme, Supersymmetry Parameter Analysis SPA, based on a consistent set of conventions and input parameters. A repository for computer programs is provided which connect parameters in different schemes and relate the Lagrangian parameters to physical observables at LHC and high energy e(+)e(-) linear collider experiments, i.e., masses, mixings, decay widths and production cross sections for supersymmetric particles. In addition, programs for calculating high-precision low energy observables, the density of cold dark matter (CDM) in the universe as well as the cross sections for CDM search experiments are included. The SPA scheme still requires extended efforts on both the theoretical and experimental side before data can be evaluated in the future at the level of the desired precision. We take here an initial step of testing the SPA scheme by applying the techniques involved to a specific supersymmetry reference point.
12 Aug 2006
TL;DR: It is shown that satisfiability for the two-variable first-order logic FO2(~,<,+1) is decidable over finite and over infinite data words, where ~ is a binary predicate testing the data value equality and +1,< are the usual successor and order predicates.
Abstract: In a data word each position carries a label from a finite alphabet and a data value from some infinite domain. These models have been already considered in the realm of semistructured data, timed automata and extended temporal logics. It is shown that satisfiability for the two-variable first-order logic FO^2(~,\le,+1) is decidable over finite and over infinite data words, where i« is a binary predicate testing the data value equality and +1,\le are the usual successor and order predicates. The complexity of the problem is at least as hard as Petri net reachability. Several extensions of the logic are considered, some remain decidable while some are undecidable.
TL;DR: The presentation of the theoretical foundation of RSABR as well as its application in solving many data mining problems and knowledge discovery in databases such as feature selection, feature extraction, data preprocessing, classification of decision rules and decision trees, association analysis.
Abstract: Since its introduction by George Boole during the mid-1800s, Boolean algebra has become an important part of the lingua franca of mathematics, science, engineering, and research in artificial intelligence, machine learning and data mining. The Boolean reasoning approach has manifestly become a powerful tool for designing effective and accurate solutions for many problems in decision-making and approximate reasoning optimization. In recent years, Boolean reasoning has become a recognized technique for developing many interesting concept approximation methods in rough set theory. The problem considered in this paper is the creation of a general framework for concept approximation. The need for such a general framework arises in machine learning and data mining. This paper presents a solution to this problem by introducing a general framework for concept approximation which combines rough set theory, Boolean reasoning methodology and data mining. This general framework for approximate reasoning is called Rough Sets and Approximate Boolean Reasoning (RSABR). The contribution of this paper is the presentation of the theoretical foundation of RSABR as well as its application in solving many data mining problems and knowledge discovery in databases (KDD) such as feature selection, feature extraction, data preprocessing, classification of decision rules and decision trees, association analysis.
TL;DR: In this paper, a collinear logarithm ln (m b 2 / m l 2 ) was derived for the low m l l 2 integrated branching ratio in the muonic case, where the error includes the parametric and perturbative uncertainties only.
TL;DR: In this article, the spectral properties of squeezed light produced by means of pulsed, single-pass degenerate parametric down-conversion were analyzed and the multimode output of this process can be decomposed into characteristic modes undergoing independent squeezing evolution.
Abstract: We analyze the spectral properties of squeezed light produced by means of pulsed, single-pass degenerate parametric down-conversion. The multimode output of this process can be decomposed into characteristic modes undergoing independent squeezing evolution akin to the Schmidt decomposition of the biphoton spectrum. The main features of this decomposition can be understood using a simple analytical model developed in the perturbative regime. In the strong pumping regime, for which the perturbative approach is not valid, we present a numerical analysis, specializing to the case of one-dimensional propagation in a beta-barium borate waveguide. Characterization of the squeezing modes provides us with an insight necessary for optimizing homodyne detection of squeezing. For a weak parametric process, efficient squeezing is found in a broad range of local oscillator modes, whereas the intense generation regime places much more stringent conditions on the local oscillator. We point out that without meeting these conditions, the detected squeezing can actually diminish with the increasing pumping strength, and we expose physical reasons behind this inefficiency.
TL;DR: Different facets of the recent progress in metal speciation in biochemistry are covered, including probing in vitro interactions between metals and biomolecules, detection, determination, and structural characterization of heteroatom-containing molecules in biological tissues, and protein monitoring and quantification via a heteroelement signal.
Abstract: A considerable momentum has recently been gained by in vitro and in vivo studies of interactions of trace elements in biomolecules due to advances in inductively coupled plasma mass spectrometry (ICP MS) used as a detector in chromatography and capillary and planar electrophoresis. The multi-isotopic (including non-metals such as S, P, or Se) detection capability, high sensitivity, tolerance to matrix, and large linearity range regardless of the chemical environment of an analyte make ICP MS a valuable complementary technique to electrospray MS and MALDI MS. This review covers different facets of the recent progress in metal speciation in biochemistry, including probing in vitro interactions between metals and biomolecules, detection, determination, and structural characterization of heteroatom-containing molecules in biological tissues, and protein monitoring and quantification via a heteroelement (S, Se, or P) signal. The application areas include environmental chemistry, plant and animal biochemistry, nutrition, and medicine.
TL;DR: The All Sky Automated Survey (ASAS) is a long-term project to monitor bright variable stars over the whole sky as mentioned in this paper, and the statistics of the distribution provides a qualitative confirmation of decades old idea of Flannery and Lucy that the W UMa-type binaries evolve through a series of relaxation oscillations.
Abstract: The All Sky Automated Survey (ASAS) is a long-term project to monitor bright variable stars over the whole sky. It has discovered 50 099 variables brighter than V < 14 mag south of declination +28 ◦ , and among them 11 076 eclipsing binaries. We present a preliminary analysis of 5384 contact, 2949 semi-detached, and 2743 detached systems. The statistics of the distribution provides a qualitative confirmation of decades old idea of Flannery and Lucy that the W UMa-type binaries evolve through a series of relaxation oscillations: the ASAS finds comparable number of contact and semi-detached systems. The most surprising result is a very small number of detached eclipsing binaries with periods P < 1 d, the systems believed to be the progenitors of the W UMa stars. As many (perhaps all) contact binaries have companions, there is a possibility that some were formed in a Kozai cycle, as suggested by Eggleton and his associates.
TL;DR: In this paper, it was shown that tetrahedral SiH4 molecules should undergo phase transitions with sixfold and eightfold coordinate Si appearing above 25 GPa, and the most stable structure found can be metallized at under a megabar and at a compression close to the prediction of Goldhammer-Herzfeld criterion.
Abstract: A way to circumvent the high pressures needed to metallize hydrogen is to "precompress" it in hydrogen-rich molecules, a strategy probed theoretically for silane. We show that phases with tetrahedral SiH4 molecules should undergo phase transitions with sixfold- and eightfold-coordinate Si appearing above 25 GPa. The most stable structure found can be metallized at under a megabar and at a compression close to the prediction of Goldhammer-Herzfeld criterion. According to a BCS-like estimate, metallic silane should be a high-temperature superconductor.
TL;DR: The quality of inferred networks dramatically improves when using data from perturbation experiments and it is concluded that the exact algorithm should be used when it is possible, i.e. when considered set of genes is small enough.
Abstract: A central goal of molecular biology is to understand the regulatory mechanisms of gene transcription and protein synthesis. Because of their solid basis in statistics, allowing to deal with the stochastic aspects of gene expressions and noisy measurements in a natural way, Bayesian networks appear attractive in the field of inferring gene interactions structure from microarray experiments data. However, the basic formalism has some disadvantages, e.g. it is sometimes hard to distinguish between the origin and the target of an interaction. Two kinds of microarray experiments yield data particularly rich in information regarding the direction of interactions: time series and perturbation experiments. In order to correctly handle them, the basic formalism must be modified. For example, dynamic Bayesian networks (DBN) apply to time series microarray data. To our knowledge the DBN technique has not been applied in the context of perturbation experiments. We extend the framework of dynamic Bayesian networks in order to incorporate perturbations. Moreover, an exact algorithm for inferring an optimal network is proposed and a discretization method specialized for time series data from perturbation experiments is introduced. We apply our procedure to realistic simulations data. The results are compared with those obtained by standard DBN learning techniques. Moreover, the advantages of using exact learning algorithm instead of heuristic methods are analyzed. We show that the quality of inferred networks dramatically improves when using data from perturbation experiments. We also conclude that the exact algorithm should be used when it is possible, i.e. when considered set of genes is small enough.
TL;DR: Melatonin attenuated diabetes‐induced alterations in glutathione redox state and HFR levels, normalized creatinine concentration and diminished urea content in serum and the examined organs, and the indole‐induced increase in the activities of the enzymes of glutathion metabolism might be of importance for antioxidative action of melatonin under diabetic conditions.
Abstract: Oxidative stress is considered to be the main cause of diabetic complications. As the role of antioxidants in diabetes therapy is still underestimated, the aim of the present investigation was to study the antioxidative action of melatonin in comparison with N-acetylcysteine (NAC) under diabetic conditions. Alloxan-diabetic rabbits were treated daily with either melatonin (1 mg/kg, i.p.), NAC (10 mg/kg, i.p.) or saline. Blood glutathione redox state and serum hydroxyl free radicals (HFR), creatinine and urea levels were monitored. After 3 wk of treatment animals were killed and HFR content, reduced glutathione/oxidized glutathione (GSH/GSSG) ratio as well as the activities of glutathione reductase, glutathione peroxidase and gamma-glutamylcysteine synthetase were estimated in both liver and kidney cortex. Diabetes evoked a several-fold increase in HFR levels accompanied by a significant decline in GSH/GSSG ratio in serum and the examined organs. In contrast to NAC, melatonin (at 1/10 the dose of NAC) attenuated diabetes-induced alterations in glutathione redox state and HFR levels, normalized creatinine concentration and diminished urea content in serum. Moreover, the indole resulted in an increase in glutathione reductase activity in both studied organs and in a rise in glutathione peroxidase and gamma-glutamylcysteine synthetase activities in the liver. In contrast to NAC, melatonin seems to be beneficial for diabetes therapy because of its potent antioxidative and nephroprotective action. The indole-induced increase in the activities of the enzymes of glutathione metabolism might be of importance for antioxidative action of melatonin under diabetic conditions.
TL;DR: Recent views on the role of some mitochondrial molecular chaperones as prohibitin, mortalin and HSP60/HSP10 complex and their modifications leading to cell transformation and cancer development are reflected and could represent modern molecular biomarkers for oncological management.
Abstract: Mitochondria are cell organelles involved in processes of cell life and death, and therefore also in tumoral transformation. Indeed, mitochondria dysfunction is a prominent feature of cancer cells. Mitochondrial proteins and DNA have also been previously studied as markers of tumorigenesis. Heat shock proteins (HSPs) are ubiquitous evolutionary conserved proteins. HSPs enhance their expression in stressed cells and they are involved in gene expression regulation, DNA replication, signal transduction, differentiation, apoptosis, cellular senescence or immortalization. This review reflects recent views on the role of some mitochondrial molecular chaperones as prohibitin, mortalin and HSP60/HSP10 complex and their modifications leading to cell transformation and cancer development. These molecules could represent modern molecular biomarkers for oncological management.
TL;DR: The applications of engineered zinc finger proteins are discussed in a context of the mechanism mediating their effect on the targeted DNA and the regulation of the expression of zinc Finger proteins and their targeting to various cellular compartments and to chromatin and non-chromatin target templates are described.
TL;DR: The OGLE-2004-BLG-343 microlensing event with peak magnification Amax = 3000 ± 1100, by far the highest magnification event ever analyzed and hence potentially extremely sensitive to planets orbiting the lens star as discussed by the authors.
Abstract: OGLE-2004-BLG-343 was a microlensing event with peak magnification Amax = 3000 ± 1100, by far the highest magnification event ever analyzed and hence potentially extremely sensitive to planets orbiting the lens star. Due to human error, intensive monitoring did not begin until 43 minutes after peak, at which point the magnification had fallen to A ~ 1200, still by far the highest ever observed. As the light curve does not show significant deviations due to a planet, we place upper limits on the presence of such planets by extending the method of Yoo et al. (2004b), which combines light-curve analysis with priors from a Galactic model of the source and lens populations, to take account of finite-source effects. This is the first event so analyzed for which finite-source effects are important, and hence we develop two new techniques for evaluating these effects. Somewhat surprisingly, we find that OGLE-2004-BLG-343 is no more sensitive to planets than two previously analyzed events with Amax ~ 100, despite the fact that it was observed at ~12 times higher magnification. However, we show that had the event been observed over its peak, it would have been sensitive to almost all Neptune-mass planets over a factor of 5 of projected separation and even would have had some sensitivity to Earth-mass planets. This shows that some microlensing events being detected in current experiments are sensitive to very low mass planets. We also give suggestions on how extremely high magnification events can be more promptly monitored in the future.
University of Tokyo1, Boston University2, Pennsylvania State University3, Brookhaven National Laboratory4, University of California, Irvine5, California State University, Dominguez Hills6, Chonnam National University7, Duke University8, George Mason University9, Gifu University10, Indiana University11, Kobe University12, Kyoto University13, TRIUMF14, Los Alamos National Laboratory15, Louisiana State University16, University of Maryland, College Park17, Massachusetts Institute of Technology18, University of Minnesota19, Miyagi University of Education20, Nagoya University21, Stony Brook University22, Niigata University23, Okayama University24, Osaka University25, Seoul National University26, Shizuoka University27, Sungkyunkwan University28, Tohoku University29, Tokai University30, Tokyo Institute of Technology31, University of Warsaw32, University of Washington33
TL;DR: In this article, the results of a three-flavor oscillation analysis using Super-Kamiokande I atmospheric neutrino data, with the assumption of one mass scale dominance, were reported.
Abstract: We report on the results of a three-flavor oscillation analysis using Super-Kamiokande I atmospheric neutrino data, with the assumption of one mass scale dominance ($\ensuremath{\Delta}{m}_{12}^{2}=0$). No significant flux change due to matter effect, which occurs when neutrinos propagate inside the Earth for ${\ensuremath{\theta}}_{13}\ensuremath{
e}0$, has been seen either in a multi-GeV ${\ensuremath{
u}}_{e}$-rich sample or in a ${\ensuremath{
u}}_{\ensuremath{\mu}}$-rich sample. Both normal and inverted mass hierarchy hypotheses are tested and both are consistent with observation. Using Super-Kamiokande data only, 2-dimensional 90% confidence allowed regions are obtained: mixing angles are constrained to ${sin }^{2}{\ensuremath{\theta}}_{13}l0.14$ and $0.37l{sin }^{2}{\ensuremath{\theta}}_{23}l0.65$ for the normal mass hierarchy. Weaker constraints, ${sin }^{2}{\ensuremath{\theta}}_{13}l0.27$ and $0.37l{sin }^{2}{\ensuremath{\theta}}_{23}l0.69$, are obtained for the inverted mass hierarchy case.